The invention relates to an adjustable camshaft, having at least one shaft, and having at least one cam package which comprises at least two different cams and/or cam contours.
A camshaft includes at least one support element, also called a tube or shaft, and at least one cam. For applications in engines, camshafts serve as a part of the valve operating mechanism, wherein the support element rotates about its longitudinal axis. The cams convert the rotary movement into longitudinal movements, and the inlet and outlet valves of the motor are controlled by these movements. In order to make it possible to optimally control the engine according to loads present, approaches for the adjustment of camshafts are found in the prior art, for example wherein different cams are made to engage with the valves, or wherein the settings of the cams, e.g. the angles of the cams to each other, are altered. In the patent publication WO 2010/040439 A1, a valve operating mechanism is described wherein a device attached outside of the camshaft enables the displacement of individual pairs of cams or groups of cam pairs, such that the different cam contours of the cam pairs serve the purpose of controlling the valves. The construction described in that document requires a large constructed space around the actual camshaft. In addition, the number of components used is relatively high, which is associated with high complexity.
In the prior art, the adjustment of the camshaft generally requires consideration of the fact that the cams can only be adjusted if the associated valves are running on the base circle of the cams, meaning if the cams are not operating the valves. For this reason, the cams must either be adjusted individually, or groups can be formed only of cams which are not engaged with the valves, at least during a phase. In the latter case, the adjustment of the cams is carried out at that point.